Chaya is the consort of Hindu God Surya. Chhaya, also spelled Chaya, is a Sanskrit word which literally means "shadow" or "shade". Chhaya is regarded as the shadow-image or reflection of Saranyu (Sangya), the first wife of Surya. Saranyu created Chhaya from her shadow, as she was unable to bear the heat of Lord Surya.

Bhairava is one of the manifestations of Hindu God Shiva. Bhairava is also known by the name Dandapani, as he holds a Danda (rod) to punish those people who are sinful. Bhairav is a Hindu Tantric deity worshiped by Hindus.

Achyuta, also spelled Acyuta, is a Sanskrit word which literally means “infallible”. It is one of the popular names of Maha Vishnu. It appears as the 100th and 318th names in the Vishnu Sahasranama (the 1008 names of Vishnu).Achyutha, according to Adi Shankara's commentary, means "one who will never lose his inherent nature and powers".

Matali is the charioteer of Lord Indra, the King of the Gods. He is often employed by Indra as a messenger on his behalf. Matali is regarded as the greatest charioteer in the world. Matali took Arjuna to the kingdom of gods.

Agni is a Sanskrit word which literally means fire. In Hinduism, Agni is regarded as the God of Fire. Agni is one of the 5 Pancha Bhoota or the five great elements. Rishi Kashyapa and Aditi are the parents of Agni Dev.

Agni is of great significance in Hinduism, and is considered as the medium that conveys offering to them in a Homa (ritual).

Vrata or Vrat is a Sanskrit word which literally means “religious vow or holy practice”. Vrata is usually practiced with prayers seeking good health fertility, long life or happiness. During vrat people chant mantras, read religious books, hear disclosures, or take silent meditation. Non vegetarian foods are avoided. Vrata is a popular practice in not only Hinduism but also Buddism and Jainism.

Hindu puranas mainly refers to 3 different types of vratas

1) Kayika-vrata - Vrata relating to the body. Physical austerity like fasting is given more importance.

2) Vachika-vrata - Vrata relating to speech. In this type of vrata importance is given to reciting the scriptures and speaking only truth.

Payovrata – A vrata or penance addressed to Hindu God Vishnu. The vrata should be followed by a devotee for 12 days drinking milk only.

Payovrata is also known as sarvayajna, sarvavrata. The vrata was first instructed to Kashyapa Muni by Lord Brahma, when muni inquired Brahmadeva regarding obtaining progeny.

Payovrata is the vrata or penance observed by Goddess Aditi to propitiate Lord Vishnu. Kashyapa Rishi asked his wife Aditi to observe Payovrata to propitiate Mahavishnu. Pleased by Payovrata Lord Vishnu take birth as Vamana for Kashyap and Aditi.

Smriti – Smriti in Sanskrit means “Recollection”. It literally means "that which is remembered". Smriti, derive authority from the Shruti, and are texts which were remembered and were spread through mouth from generation to generation.

Smriti consists of texts such as

Puranas
Dharmasutras and Dharmasastras
The Mahabharata
The Ramayana
The Arthasasastras
The Kavyas

Shruti or Shruthi in Hinduism. In Sanskrit, Shruti literally means "that Which Is Heard". Sruti means the knowledge which was heard by revelation. It refers to the most authoritative, ancient sacred texts consisting of the base of Hinduism.

Shruti (What Is Heard) comprises of the four Vedas (Rig Veda, Yajur Veda, Sama Veda and Atharva Veda) including its four types of attached texts – the early Upanishads, the Brahmanas, the Samhitas and the Aranyakas.

Ganesha or Ganesh is a Sanskrit compound word Gana and Isha. Gana meaning a group. Isha meaning “lord or master”. Ganesa is the chief of Shiva's army. Ganapathi is also one of the most worshiped Gods in Hinduism. Read more info here